Concentrator



Aprii 1945- A. B. BOUWER ET AL V 2,373,452

CONCENTRATOR Filed Aug. 14, 1943 (W Z ig i\ \W W? 7 9 10 PEG. 8

I Patented Apr. 10, 1945 CONCENTRATOR I Adam Barnard Bouwer and LeslieDorfman, Johannesburg, Transvaal, Union of South Africa ApplicationAugust 14, 1943, Serial No.-498,658

In the Union of South Africa March 2, 1943 This invention relates toconcentrators, more particularly to apparatus for concentrating mineralvalues fromsands and the like.

The object of the invention is, in a concentrator having the form of asloping table down the length of which the material to be concentratedis washed, to provide means whereby the fiowing stream is renderedturbulent not only by shaking, rocking or swinging the table, butparticularly by providing cells or pockets having open tops andbroken,or slotted wall areas, and a floor of fibrous material such as corduroy,blanket, mats or the like over which-the stream tobe treated fiows. Theconstruction is designed to facilitate the removal and replacement ofthe blankets or the like for the recovery of the concentrates caughttherein. In other words the object of the invention is to provide atable which shall have the capacity of a sluice box, the ease ofmanipulation of a corduroy table, and the efficiency of a shaking table.The invention combines in one apparatus the use of the movement of ashaking table, the surface of corduroy which can easily be cleaned, andthe capacity of a riffled strake or sluice box.

The invention is illustrated diagrammatically, and in its preferredform, in the accompanying drawing in which Fig. I is a side elevation,

Fig. II an enlarged ectional view;

Fig. III a sectional elevation, and

Fig. IV a plan, showing on a larger scale and table having a lengthabout seven times its widthand usually sloping at an angle of about 5with the horizontal.

The table I is hung in stirrups 2 which are free to swing on crank arms3 supported in suitable fixed bearings on uprights 4 fixed on eitherside of the table I. The table is shaken, swung or vibrated for examplelay-means of a pitman 5, with one end connected to the bottom of thetable I and the other journalled to an eccentric 6 on a cross shaft Iadapted to be driven at some hundreds of revolutions per minute. Thefloor 8 of the table I, is fiat and is covered, see Fig. III, preferablywith corduroy 9 with the riilies I0 running across the length of thetable. This fibrous covering is protected by a metal sieve. For instanceperforated or expanded metal sheets may be used or preferably wire meshscreens, as

shown, are fastened over the corduroy 9 and lie close down on it. II isa layer of wire screen having a coarse mesh for instance a, half inch.Over this first wire screen II is placed a second I2-of similar mesh butusually made of a heavier gauge wire. These wire screens. II, I2, placedone above the other on the corduroy 9 provide the desired concentratingcells I3, which, it will be understood, form pockets or pans all overthe surface of the table and each has irregular sides I4 (Figs. III andIV) the amount of irregularity depending on how closely the meshes ofthe two wire screens II, I2 superimpose on one another. All the sidesare broken by slottedopenings between the wires as shown in Figs. IIIand IV.

There areth'erefore'preferably three layers 9, II, I2, onfithe surfaceit of the table I, namely the corduroy 9, a-screen of wire II, and afurther screen I2 of the samesize mesh but preferably of heavier gaugewire; There maybe one or more-further layers of' slotted wearing platesdown which large stones or the like may slide, or further screens, butusually two are 'sufiicient. These layers are held in place bylongitudinally placed strips or battens I5 clamped by screws I6 at theedges I! of the table I and conveniently in the corners made by theupstanding edges ll of the table.

The table I has ashute' or feeding platform I8 from which the materialis washed onto the head I9 of the table generally through a screen 20,the latter conveniently placed for removing lumps, stones, sticks orother objectionable and oversize material. At the foot 2| of the tableprovision is made to remove the treated sand after separating the water.The dirty water may be run to settling tanks and clarified, by the useof a fiocculating medium such as lime or otherwise. Ihe clarified wateris returned to the head of the table for re-use.

The action of the concentrator, according to this invention, and whenworking for instance on the sands of an old mine dump, is as follows.The sand is washed by the use of water from nozzle 22 onto the head I9of the table I, using an ample supply of water. The stream flows bygravity down the sloping table I, through the screens II, I2 when theheavier particles fall onto the corduroy 9. The fine particles of valuein the sand, some-of which have been freed from the sand by weatheringor otherwise, are caught in the corduroy 9 in the well known manner.Whilst in some cases heavy and larger particles are caught in thepockets I3. The stream 23 (Fig. III) however sinking is. not allowed toflow smoothly, it must make its way in and out of each cellularcompartment 1 3 on the fi0or.8 of the table I and is kept in a turmoilby having to flow between the strands of the wire mesh H, l2, that isthrough the slotted walls 14 of the cells H. Al; the same time the tableI swings rapidlv through a small amplitude and-generally longitudinally.This.

means that each small 's'ection'of the stream is bufietted by the movingwire meshes, H, 12 as it passes from one cell I3 to the next. It is bothscreens of the same size mesh opening but difiering in diameter of wire,and clamping means for removably holding the fibrous covering and thescreens in close contact with one another and in place on the table.

2. In a concentractor, the combination of an elongated table slopinglongitudinally, a liquid supply for causing {now down the length of the,table, means for oscillating the table in covering on the floor of thetable, two layers of well known that fine gold is best caught in waterandthat clean concentrate cured in narrow deep riiilesl. v

This invention provides therefore what is considered the best means forconcentrating values is es P cleanly and eificiently from,;inat,erialthe values in small sizes.

The length of the table 1 allows the eoncenk tration to be carried onfor a reasonablylon'g period. with ut the ne essity tor removing. and.changing the char d. cord oy 8-. The. t me.- between. cleaning will. depnd. on the. richnes Qt. the material... Due to the s llu et surface 8-.o the table and 'itsconstant agitation a Mas uestity ofrmaterial may. etrea ed rap ly and eifi-, ciently.

It will be obvious. that the invention uit hie for use in. cen entratinsnest f as i ns from numerous. materials, in whi h the values, can. b wased out. and which. aresms i-snoush. abs aught. inthe. cell e Whatwe. sei. new and de ire to secure y Letters Paisntisi. a Y

1. In a concentrator,thecomhinat on Q52 an elongated table sloping.longitudinally, a liquid supply for causing a fiow down theln tb 01 thtable, means foroscillatms, the ta le lensitudinal direction. a 1removab e fibrous sheet covering on manner. of the t blet twolayers of.

wire mesh screen. dispo ed above. aid.

longitudinal direction, a removable fibrous sheet wire mesh screensuperimposed on said covering,

both screens of the same size mesh opening but i diiieringin'diamet'ejrof wire and running paralil with" the length of the table and at rightangles thereto'respectively, and clamping means :ior-removably holdingthe fibrous covering and w the screensim close-contact with one anotheranother. and. runnin narallelwith the len th of he table and at. ri ht.an les. thereto respectively. meensifor: stimat ng-the table. to ausethe wire in. he scre ns yins. across the tab e to. tempo ari y'heat' agi st the current of. liquid: flowing own th n th o the table, andclampin means for removably-holding th corduroy cover ns. and. th ereensin lose contact with. one

hlase n hetahle.

ADAMBARNABD BQUWER. LESLIE. DORFMAN.

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